Dermoid cyst

The parents of a 2-year-old boy were curious about the “bump” near their son's eye, which they had first noticed about 6 months earlier. The cystic mass in the right medial canthal region measured 8 mm in diameter. It was nontender.

Drs Edmond K. H. Liu and Alexander K. C. Leung of Calgary, Alberta, made the diagnosis of dermoid cyst.

These cysts result from sequestration of epidermal cells along embryologic closure lines.

Dermoid cysts are lined by keratinizing stratified squamous epithelium that contains dermal appendages, such as hair follicles and sebaceous glands. The usually solitary and asymptomatic masses occur most frequently on the head and neck.

Approximately 40% of the lesions are periorbital; about 30% occur in the eyebrows. Although dermoid cyst communication with the CNS is extremely rare, it is more common with cysts in the nasal region.

Surgical excision is the treatment of choice. This youngster's cyst was removed; his recovery was uneventful.